--- a/src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeManager.cpp	Fri Aug 31 12:41:00 2018 +0200
+++ b/src/hotspot/share/jfr/recorder/checkpoint/types/jfrTypeManager.cpp	Fri Aug 31 07:03:46 2018 -0400
@@ -149,7 +149,9 @@
 
 void JfrTypeManager::write_type_set() {
   // can safepoint here because of Module_lock
+  MutexLockerEx cld_lock(SafepointSynchronize::is_at_safepoint() ? NULL : ClassLoaderDataGraph_lock);
   MutexLockerEx lock(SafepointSynchronize::is_at_safepoint() ? NULL : Module_lock);
+
   JfrCheckpointWriter writer(true, true, Thread::current());
   TypeSet set;
   set.serialize(writer);